Yesterday, I went to the garage to start a fire in the boiler. It was a windy and cold morning (-9C if I remember correctly but felt much colder with 50km/hr winds gusting to 70 km). The temperature reading was 20C on the controller. I hadn't fed the boiler late at night as I usually do because I'd run out of wood in the garage and it was too cold and dark to go get more. I'd been working long hours and slacked off on wood prep. I went out to the woodshed to get some splits and when I returned after monkeying the tractor, the temperature on the controller read 31C. I checked inside to see if I had lit a fire (in a dazed stupor) but I had not.
As it turns out my wife had fired up the oil furnace. The pumps were on and the heat from the heat exchanger in the furnace must have heated the boiler/barn etc. I turned the oil burner back to 50 where it usually sits and heated up the house with wood.
I never made the connection in my mind that the oil burner and water to air HX (and conversely air to water HX) would actually heat the boiler and plumbing. That phenomenon actually gives the system a bit of freeze protection that I didn't know I had, so it is a pleasant surprise.
Three years in and still learning.
As it turns out my wife had fired up the oil furnace. The pumps were on and the heat from the heat exchanger in the furnace must have heated the boiler/barn etc. I turned the oil burner back to 50 where it usually sits and heated up the house with wood.
I never made the connection in my mind that the oil burner and water to air HX (and conversely air to water HX) would actually heat the boiler and plumbing. That phenomenon actually gives the system a bit of freeze protection that I didn't know I had, so it is a pleasant surprise.
Three years in and still learning.